Expression of P2X7, caspase 1 and caspase 11 mRNA levels. Male C57bl/6 mice were exposed to vehicle (aerosolised saline) or LPS (1 mg/ml) for 30 minutes. Lung tissue and BALF was collected at different time after the exposure. Lung tissue levels of P2X7(A), caspase 1 (B) and caspase 11 (C) mRNA expression were detected by real time PCR. Data are represented as mean ± S.E.M. for n = 6 animals in each group. Statistical significance was determined using Mann–Whitney U test. # = P < 0.05, denoting a significant difference between the LPS exposed and vehicle exposed wild-type groups.